US2019346548A1PendingUtilityA1
Filtering to address range walk effect in range-doppler map
Assignee: GM GLOBAL TECH OPERATIONS LLCPriority: May 11, 2018Filed: May 11, 2018Published: Nov 14, 2019
Est. expiryMay 11, 2038(~11.8 yrs left)· nominal 20-yr term from priority
G01S 7/36G01S 13/931G01S 13/42G01S 13/582G01S 13/5242G01S 13/89G01S 7/288G01S 2007/2883G01S 7/2883
39
PatentIndex Score
0
Cited by
0
References
0
Claims
Abstract
A radar system and method of processing one or more return signals obtained by a receive section of a radar system resulting from transmitting one or more signals involve a transmit section to transmit the one or more signals, and a receive section to receive the one or more return signals resulting from reflection of the one or more signals by a target. The system also includes a processor to process the one or more return signals using a two-stage fast Fourier transform (FFT) to obtain a range-Doppler map indicating energy levels at each of a set of range values and a set of Doppler values, to filter the range-Doppler map using a kernel sized according to an estimate of a number of the set of range values over which the energy levels above a threshold value are spread, and to perform target detection based on a result of filtering.
Claims
exact text as granted — not AI-modifiedWhat is claimed is:
1 . A radar system, comprising:
a transmit section configured to transmit one or more signals; a receive section configured to receive one or more return signals resulting from reflection of the one or more signals by a target; and a processor configured to process the one or more return signals using a two-stage fast Fourier transform (FFT) to obtain a range-Doppler map indicating energy levels at each of a set of range values and a set of Doppler values, to filter the range-Doppler map using a kernel sized according to an estimate of a number of the set of range values over which the energy levels above a threshold value are spread, and to perform target detection based on a result of filtering.
2 . The radar system according to claim 1 , wherein a number Nchirps of the one or more signals is transmitted by the transmit section in one frame, and a number of samples Nsamples of each of the Nchirps signals is obtained.
3 . The radar system according to claim 2 , wherein the processor is further configured to determine integration time Tint as:
T int =N samples ·F s ·N chirps , where
Fs is the frequency at which the number samples is obtained.
4 . The radar system according to claim 3 , wherein the processor is further configured to estimate a number of elements of the kernel as:
N
cells
=
[
T
int
R
samples
R
ma
x
d
]
,
the set of range values is from 0 to Rmax, which is a maximum unambiguous target range, Rsamples is a number of increments from 0 to Rmax, and d is a Doppler value within the set of Doppler values associated with the number of range values over which the energy levels above a threshold value are spread.
5 . The radar system according to claim 4 , wherein each of the elements of the kernel has a value of 1/Ncells.
6 . The radar system according to claim 4 , wherein the processor is configured to filter the range-Doppler map to obtain the result of the filtering by convolving the Rsamples number of energy levels associated with the Doppler value d with the Ncells number of elements of the kernel.
7 . The radar system according to claim 1 , wherein the radar system is a multi-input multi-output (MIMO) radar system.
8 . The radar system according to claim 1 , wherein the radar system is within or on a vehicle and is configured to detect a location and speed of an object relative to the vehicle.
9 . A method of processing one or more return signals obtained by a receive section of a radar system resulting from transmitting one or more signals, the method comprising:
performing a two-stage fast Fourier transform (FFT) to obtain a range-Doppler map indicating energy levels at each of a set of range values and a set of Doppler values; filtering the range-Doppler map using a kernel sized according to an estimate of a number of the set of range values over which the energy levels above a threshold value are spread; and performing target detection using a result of the filtering.
10 . The method according to claim 9 , further comprising transmitting a number Nchirps of the one or more signals and obtaining a number of samples Nsamples of each of the Nchirps signals.
11 . The method according to claim 10 , further comprising determining integration time Tint as:
T int =N samples ·F s ·N chirps , wherein
Fs is the frequency at which the number samples is obtained.
12 . The method according to claim 11 , further comprising estimating a number of elements of the kernel as:
N
cells
=
[
T
int
R
samples
R
ma
x
d
]
,
the set of range values is from 0 to Rmax, which is a maximum unambiguous target range, Rsamples is a number of increments from 0 to Rmax, and d is a Doppler value within the set of Doppler values associated with the number of range values over which the energy levels above a threshold value are spread, and setting a value of each of the elements of the kernel to 1/Ncells.
13 . The method according to claim 12 , wherein the filtering the range-Doppler map to obtain the result of the filtering includes convolving the Rsamples number of energy levels associated with the Doppler value d with the Ncells number of elements of the kernel.
14 . The method according to claim 9 , further comprising detecting a location and speed of an object relative to a vehicle based on the target detection.
15 . A vehicle, comprising:
a radar system, comprising: a transmit section configured to transmit one or more signals; a receive section configured to receive one or more return signals resulting from reflection of the one or more signals by a target; and a processor configured to process the one or more return signals using a two-stage fast Fourier transform (FFT) to obtain a range-Doppler map indicating energy levels at each of a set of range values and a set of Doppler values, to filter the range-Doppler map using a kernel sized according to an estimate of a number of the set of range values over which the energy levels above a threshold value are spread, and to perform target detection based on a result of filtering; and a controller configured to augment or automate operation of the vehicle based on the target detection.
16 . The vehicle according to claim 15 , wherein a number Nchirps of the one or more signals is transmitted by the transmit section in one frame, and a number of samples Nsamples of each of the Nchirps signals is obtained, and the processor is further configured to determine integration time Tint as:
T int =N samples ·F s ·N chirps , where
Fs is the frequency at which the number samples is obtained.
17 . The vehicle according to claim 16 , wherein the processor is further configured to estimate a number of elements of the kernel as:
N
cells
=
[
T
int
R
samples
R
ma
x
d
]
,
the set of range values is from 0 to Rmax, which is a maximum unambiguous target range, Rsamples is a number of increments from 0 to Rmax, and d is a Doppler value within the set of Doppler values associated with the number of range values over which the energy levels above a threshold value are spread.
18 . The vehicle according to claim 17 , wherein each of the elements of the kernel has a value of 1/Ncells.
19 . The vehicle according to claim 17 , wherein the processor is configured to filter the range-Doppler map to obtain the result of the filtering by convolving the Rsamples number of energy levels associated with the Doppler value d with the Ncells number of elements of the kernel.
20 . The vehicle according to claim 15 , wherein the radar system is a multi-input multi-output (MIMO) radar system.Join the waitlist — get patent alerts
Track US2019346548A1 — get alerts on status changes and closely related new filings.
We store only your email — no account needed. See our privacy policy.